| Feature | Structured Data | Semi-Structured Data | Unstructured Data |
|---|---|---|---|
| Format | Fixed schema (tables, rows, columns) | No strict schema but has tags/metadata | No predefined structure |
| Examples | SQL databases, Excel sheets | JSON, XML, NoSQL databases | Emails, videos, social media posts |
| Storage | Relational Databases (MySQL, PostgreSQL) | NoSQL Databases (MongoDB, Cassandra) | File systems, Data Lakes, Object Storage |
| Processing | Easy with SQL queries | Requires parsing and mapping (XPath, XQuery, JSONPath) | Needs AI, NLP, or big data tools |